Meghan Markle, 36, and Prince Harry, 33, announced their engagement in November, and last week revealed their wedding will take place on 19 May 2018.
As Kate Middleton is pregnant, many assume the couple have chosen to wait until well after her due date in April.
But there could be another reason for their choice, and it is one the Royal Family has made for many of their important weddings.
Looking back, no other major wedding has taken place on 19 May in history.
Famous people have of course married on this day before – including Facebook’s Mark Zuckerberg and Hollywood actress Jessica Alba – but none with any major significance.
So the couple would not have any comparisons with other nuptials that came before theirs.
The same is true of the Queen’s wedding date, 20 November 1947, with no other historically important weddings on her chosen date at the time.
This rule applies to the weddings of Prince Charles and Princess Diana and Prince Andrew and Sarah Ferguson.
However, the same cannot be said of Prince William and Kate Middleton who wed on 29 April 2011. They unfortunately share their anniversary with Adolf Hitler and Eva Braun.
While the royals are on the whole careful not to wed on the same day as others throughout history, superstitious people may have been surprised by the wedding date Harry and Meghan chose.
This is partly thanks to the old saying which goes: “Marry in May, rue the day.”
Stephanie Coontz, a history and family studies professor at The Evergreen State College, and author of Marriage, a History: How Love Conquered Marriage, told Global News: “It was considered a bad omen to marry in May back in Roman times because May was the month of the Feast of the Dead, and three days of that month were devoted to cleansing the evil dead spirits.”
And an old Celtic poem also warns against marrying on a Saturday – with many other days of the week considered a better choice.
It reads: “Monday for wealth, Tuesday for health, Wednesday the best day of all,
“Thursday for losses, Friday for crosses, And Saturday no luck at all.”